(1) Field of the Invention
The present invention relates to a method for high-speed boiling of soybeans, adzuki beans, kintokimame or a large kind of adzuki beans, midorimame or green beans, zatto or uncultivated beans, tebo or a kind of black-eye pea, kidney beans, mustard beans and other types of cooked beans, fermented soybeans, miso, tofu, soy sauce, mustard, bean jam, and sweet jelly of beans, and an apparatus therefor.
(2) Description of the Prior Art
When manufacturing or processing cooked beans, fermented soybeans, miso, soy sauce and other types of beans, boiling the beans is necessary. Heretofore, an apparatus for boiling beans is disclosed in Japanese Patent Publication (Kokai) No. 254446 of 1993 (Heisei 5). In a method of boiling beans of Japanese Patent Publication (Kokai) No. 254446 of 1993 (Heisei 5), as shown in FIG. 10, beans 111 are inserted loosely into a heating kettle 110, or beans 111 are put in a basket and inserted into a heating kettle 110 open to the atmosphere, when the shape of grained beans is required for cooked beans, and a given amount of water 112 is added to the beans. The beans and water in the heating kettle 110 are heated under the atmosphere, by sending steam heated in a boiler into a jacket 113 provided at the lower portion of heating kettle 110. Further, a slightly pressurized kettle in which the inside thereof is slightly pressurized to the order of 0.8 atmospheric pressure. In the process of boiling the beans, valve 114 through which steam is sent to the jacket 113 is opened and shut by a hand or electronically by a worker in constant attendance, by which the temperature within heating kettle 110 is controlled.
In the process of boiling the beans, the supply of heat is carried out considering the characteristic of various beans in the process of boiling the beans. Even though the beans are of the same sort, the quality of beans is affected by the weather since beans are agricultural products. Therefore, the amount of water, how to heat, and the boiling period of the beans are controlled by experience and skill of a worker which were taken over from before the Heian Era.
However, for carrying out the process of boiling of the beans, even for boiling beans of 60 Kg, 1 to 1.5 hours are required, and for boiling beans of 300 Kg, 2 to 3 hours, namely 7,200 to 10,800 seconds are required. In this work, in order to watch for an abnormal state, a worker must be in constant attendance upon the process of boiling the beans. However, in the work of boiling of beans, how to complete the boiling of beans varies with sorts of bean material, the state of beans as hinemame or old beans after the lapse of many years, and the adjustment in hot taste in the case of mustard beans or with each preparation of heating kettle 110. Therefore, in spite of a skilled worker, it was difficult to obtain homogeneous cooked beans. To explain this further in detail, to boil beans in a conventional method means to change the nitrogen component contained in beans from unmodification region into modification region by steam or heat, wherein the chain combination HO--HO--HO-- of starch contained in beans reacts with hydrogen to break into parts by heat energy of steam, for many hours, by which the starch is sweetened. When changing the nitrogen component contained in beans from unmodification region into appropriate modification region, temperature such as 100.degree. C. is needed under atmospheric pressure, or a temperature such as 112.degree. C. is needed under a slightly higher pressure of 0.5 atm. Therefore, heating becomes excessive. Since the flow of steam introduced is fast, even though it is desired to change nitrogen component contained in beans into the appropriate modification region, a portion of beans reaches a supermodification region, by which the quality of product is worsened generating a loss in product.
Further, in this conventional process of boiling of beans, the highest temperature within the kettle in the case where a kettle is opened to the atmosphere is 100.degree. C., and the highest temperature within the kettle in the case of slightly pressurized kettle 110 where a lid is attached to the kettle is only 116.degree. C. Further, a rise in temperature within heating kettle 110 to the highest temperature takes many hours, and many hours are required to finish boiling the beans. Further it was difficult to make vital germs of thermostable spore germs die out. However, when the time of boiling of beans is longer, beans are reduced to pieces, or the nitrogen component turns into a supermodification region so that quality of product is worsened. Further, if the beans are heated to above the temperature needed for boiling of beans, browning, spoiling of taste, deterioration of starch and other effects are generated so that product is inferior in quality and graded down. Heretofore, it was thought that even if beans are treated under high pressure and high temperature, the same defects as the said defects will be generated by turning into the supermodification region (excessive cooked region).
Further, heating kettle 110 takes up a large working space, which prevents rationalization in a work. Further, large amounts of moisture and heat loss are generated by radiant heat from around heat kettle 110 and waste steam is released from the upper portion of heat kettle 110, by which energy costs are increased and the surrounding work area is worsened.
Therefore, young workers do not remain in occupations of beans boiling work, and a rise in age of workers progresses.